This landmark transformation of technical regulations was somewhat inevitable, given the environmental concerns that have marginalised the two-stroke engine as a practicable power source for street motorcycles. The new four-stroke MotoGP series thus brings racing more in line with the global streetbike market, delivering more direct feedback to streetbike development and allowing fuller exploitation of racing success in the marketplace. The new four-stroke bikes, with engines of up to 990cc, promise to be the fastest racing motorcycles ever with power outputs in excess of 200 horsepower.

The Marlboro Yamaha Team is at the vanguard of Grand Prix racing’s new era of technology. The team’s well-established duo of Max Biaggi and Carlos Checa raced their YZR500 two-strokes for the last time at last November’s Rio GP and now direct all their attention to the factory’s awesome YZR-M1 four-stroke. They are currently undertaking an intensive testing programme with the all-new YZR-M1, which was the first of the new breed to hit Europe earlier this year. The bike already proved quicker than its two-stroke predecessor in tests at Czech track Brno in July and the team’s focus from now on will be to ensure it is better than all rival two and four-strokes.

Because Grand Prix racing is a contest of cutting-edge technology that looks resolutely forward, the sport rarely takes time to look back and remember the bikes and riders that were the conquerors of their time. But as we move from one era to another, perhaps this is the moment to do just that.

Yamaha enjoyed enormous success during the 500 two-stroke era, taking 120 Grand Prix victories, ten rider World Championships and nine constructors’ titles. Coincidentally the partnership between Marlboro and Yamaha began at the time that the two-stroke first conquered 500 racing. Two-strokes had already grown to dominate the smaller GP classes, their two-for-one power stroke technology giving the engines a higher power output from a given capacity than any four-stroke. Italian legend Giacomo Agostini became the first man to win the 500 crown on a two-stroke machine when he took the 1975 title aboard his inline-four Yamaha OW26.

Agostini later went on to team management, establishing Marlboro Yamaha Team Agostini in the early eighties. Ago’s first star rider was Kenny Roberts, who had already won a hat-trick of world titles with Yamaha from 1978 to 1980. Sadly the American’s partnership with his predecessor didn’t produce a fourth crown, but his final bid for world glory in 1983 did produce one of the most memorable 500 World Championship battles. Roberts fought all season with Freddie Spencer’s slower but more nimble Honda NS500, finally missing the title by just two points.

The following season Agostini did win his first crown as a team chief, guiding young American Eddie Lawson to the 500 World Championship aboard his Marlboro Yamaha Team Agostini YZR500. The archly talented Lawson went on to win two more titles with the squad in 1986 and 1988 before taking a year’s sabbatical with Honda. He returned to Yamaha in 1990, joining the team established by Roberts, Marlboro Yamaha Team Roberts. Lawson didn’t win the title that year, however. Instead the crown went to fellow Californian Wayne Rainey, who’d started his GP career with Roberts’ Marlboro Yamaha 250 outfit in 1984.

Rainey dominated 500 GP racing during the 1990, ’91 and ’92 seasons, matching his mentor’s achievement of a 500 title hat trick. And he might have made it four in a row if he hadn’t been paralyzed in a tragic accident towards the end of the 1993 campaign.

Rainey’s team-mate Italian Luca Cadalora took over as Roberts’ big hope during the two subsequent seasons, winning four GPs and finishing second in the 1994 World Championship. In 1996 Roberts changed the team’s emphasis to supporting up-and-coming GP riders, running Norick Abe, Jean-Michel Bayle and eldest son Kenny Roberts Junior, who went on to win the 2000 title with Suzuki. Marlboro Team Roberts then created its own GP bike, the Modenas KR3, a unique machine built to challenge the supremacy of the Japanese factories.

In 1999 a new team was created, the Marlboro Yamaha Team, wholly owned by the Yamaha factory. Two new riders were signed – Max Biaggi and Carlos Checa. Over the next three seasons Biaggi’s challenge for the World Championship would grow in strength. He was fourth overall in 1999, third in 2000 and finished last season as runner-up. He took a total of six GP victories and 13 pole positions with the Marlboro Yamaha Team, while Checa scored no less than seven runner-up finishes.

Biaggi and Checa will race the YZR-M1 four-stroke for the first time at this year’s season-opening Japanese GP on April 7. They will take on four-stroke machines from Honda, Suzuki and Aprilia, as well as two-stroke machines from Honda, Proton and Yamaha. Three two-rider squads will continue to run YZR500s alongside the Marlboro Yamaha Team’s YZR-M1s. More four-stroke machines, from Ducati and Kawasaki, are expected to join the MotoGP series in 2003.

The awesome YZR-M1 is the bike with which Yamaha aims to conquer MotoGP’s new four-stroke era.  The YZR-M1 for Mission One was the first of the new breed of GP four-strokes to hit the racetracks, and last year Marlboro Yamaha Team riders Max Biaggi and Carlos Checa had a number of outings on the machine, giving their invaluable input while maintaining their focus on the last-ever 500cc World Championship.

The M1’s inline four cylinder engine configuration is the same as the factory’s award-winning range of sports streetbikes – the R1, R6 and R7 – but that’s where the similarity ends, for while Yamaha has put its confidence in a tried and trusted engine layout, the M1 is an ultra-special prototype featuring new technology that will help Yamaha maintain its edge on the street. Man behind the M1 is Masakazu Shiohara, the creative genius who started designing Yamaha GP winners during the seventies. In the late nineties Shiohara designed the YZM400F motocross engine, his first four-stroke and the motor that revolutionised motocross. Now Shiohara is repeating that journey, taking Yamaha’s GP road racers from the two-stroke era into their four-stroke future.

Work began on the machine soon after the decision to switch to four-stroke GPs and the bike commenced track development during 2000. In May 2001 the M1 became the first of the new four-strokes to run in Europe when it underwent tests at Italian track Mugello. And three months later Marlboro Yamaha Team rider Carlos Checa proved its potency by surpassing the 500 pace during a race simulation at Brno in the Czech Republic.

With around 200 horsepower available from the 20-valve motor, it was perhaps no surprise that the YZR-M1 was so fast straight out of the box. But peak power is not the overriding concern of the M1 design team, now headed by Project Leader Ichiro Yoda. Yamaha could easily obtain more power from the M1 motor but their goal is to create a manageable motorcycle that gels with its riders, not a fire-breathing beast that is hard to tame. The M1 must also look after its tyres over full-race distance and be economical on fuel, since gas tanks must carry no more than 24 litres.

Although the M1 makes more horsepower than its YZR500 two-stroke predecessor, it is easier on tyres thanks to the four-stroke’s easygoing power delivery. Riders find the bike more user-friendly for the same reason.

Yamaha engineers chose the inline four-cylinder engine after considering V4 and three-cylinder options, because they believe the four works best with the chassis, which is derived from the marque’s sweet-handling YZR500 GP bike. Like the 500, the M1 chassis features a huge range of adjustability, allowing riders to fine tune chassis character to suit their own riding styles.

This season the YZR-M1 goes head to head with a variety of rival machines – three-cylinder, four-cylinder and five-cylinder four-strokes and three and four-cylinder two-strokes. It’s an incredible mission but Yamaha has its sights set on achieving "Mission One" and is confident of success.

2002 YAMAHA YZR-M1 SPECIFICATIONS

• Engine - Liquid-cooled inline four-cylinder four-stroke, five valves per cylinder
• Ignition - programmable CDI with adjustable mapping
• Power - Around 200 horsepower at 14,500rpm
• Top speed - In excess of 320kmh/200mph
• Transmission - six-speed cassette-type gearbox, with alternative gear ratios available. Dry multiplate slipper clutch. Chain final drive.
• Chassis - twin-spar aluminium frame, multi-adjustable steering geometry/wheelbase/ride height. Aluminium swing-arm.
• Suspension - Ohlins upside down front forks and Ohlins rear shock, all adjustable for pre-load, high and low-speed compression and rebound damping. Alternative rear suspension links available
• Wheels - Marchesini 17in front, 16.5in rear, available in a variety of rim widths
• Tyres - Michelin, 17in front, 16.5in rear, available as slick, intermediate, wet and hand-cut tyres.
• Brakes - Brembo, two 305mm carbon front discs, two four-piston calipers. Single 220mm stainless steel rear disc, twin-piston caliper
• Dry weight - 145kg